To concentrate to emit fully to absorb atom photon
LESSON 2
| Light Amplification by the Stimulated Emission of Radiation. Laser усилениесветаспомощьюиндуцированногоизлучения | coherent когерентный |
| monochromatic монохроматический (одноцветный) | to emit излучать |
| partially reflecting mirror частичноотражающеезеркало | ruby laser рубиновыйлазер |
| to coil обматывать, извиваться | intermittent прерывистый |
| totrigger вызывать, провоцировать, запускать | to excite возбуждать |
| to amplify усиливать | rubylaser лазернарубиновомкристалле |
7. Why do we call lasers the solution looking for a problem?
Reading and speaking activities
Words and expressions from the text
| in (to do someone else’s job temporarily while they are not available to do it ) | ||
| stand | ||
| for (if a letter, an abbreviation, or a symbol stands for something, that is what it means or represents) |
8. Fill in the gaps with the propositions.
a) The letters ERM stand ____ Exchange-Rate Mechanism.
b) Lorraine was ready to stand ___if Helen got sick.
9. Read the text. Be ready to describe the process of laser beam generation.
The acronym LASERstands for Light Amplification by the Stimulated Emission of Radiation. Laserlight differs from ordinary light in three ways:
a) itis monochromatic, that is, it consists of a single wavelength (colour);
b) it is coherent (organised), that is, all the photons vibrate in phase with one another in space and time; and
c) it is highly directional, emitted as a relatively narrow beam in a specific direction.
The type of laser described in this lesson is the ruby laser, which uses a cylinder made of a ruby crystal. A fully reflecting mirror is placed on one end and a partially reflecting mirror on the other. A high-intensity light tube is coiledaround the ruby cylinder to provide an intermittent (non-continuous) flash of white light that triggers the laser action. The flashes exciteelectrons in the atoms in the ruby to a higher energy level. Upon returning to their normal state, the electrons emit photons of ruby-red light. At first the photons are emitted in all directions. The mirrors reflect some of the photons up and down the cylinder. Photons from one atom stimulate emission of photons from other atoms and the light intensity is rapidlyamplified. The mirrors reflect the photons back and forth inside the ruby crystal, continuing this process of stimulated emission and amplification. Finally,the photons leave the cylinder through the partial mirror. Thisisabeamoflaserlight.
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10. Match the words and word combinations.
| that is | быстро, стремительно |
| fully reflecting mirror | интенсивность |
| rapidly | световойколодец |
| intensity | направленный |
| differ from | вибрировать |
| lighttube | полностью отражающее зеркало |
| vibrate [vaɪˈbreɪt] | вспышка |
| flash | отличаться от |
| directional | иначе говоря, другими словами |
11. Fill in the gaps with the appropriate word.
(to) amplify amplified amplification
a) These stories only _________ her fears.
b) an ___________ guitar
c) Would you care ________________ that remark?
d) …a number of such photons is proportional to coefficient of _______________
Emit(ted) emission
a) He _________ a low loan.
b) Pulsars ___________radiation.
c) Stimulate _________
Intensity(intensified) intensify intensive
a) The cross-examination increased in ____________.
b) He was surprised by ____________________ of her emotions.
c) After six-months` ______________ training, she was ready to fly the aircraft.
d) Economic conditions _____________ the pressure on industry to raise prices.
Partial partially part (noun, adverb)
a) The patient may only make a ________ recovery.
b) He was only _________ to blame for the accident.
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c) What __________ of America do you come from.
d) The medical exams are ________ written, _________ practical.
Directional direct(ed) direction
a) a ____________ antenna
b) His angry is mainly _____________ to his father.
c) Our efforts are primarily ___________ towards helping children who live in poverty
d) I`d give you a lift, but I`m going in the opposite ________________.
Reflect (ed) reflection
a) Anna stared at her ______________ in the hall mirror.
b) The lake ________________ the surrounding mountains.
c) Pale colours _____________ light.
d) Your choice of clothes is ___________________ of your personality.
Coherent coherence
a) A common religion ensures the _____________ of the tribe.
b) Finally! A textbook that provides a ______________ approach to the subject.
c) My head hurt so much I couldn`t give a _____________ answer.
12. Listen to part of a talk about lasers. Match the words in the box with the labels 1-8 in the diagram below.
ruby crystal atom light tube mirror power source photon laser beam partial [ˈpɑː.ʃᵊl] mirror
Script:
… and as Jenny said, my name is Lee. So, Jenny had been explaining what laser light is, and if there are no questions, we can now turn to the next section of the talk, in which I`m going to outline the basic components of a laser and at this point I`d like you to look at the diagram which is coming up on the screen now.
Right, basically you`re looking at a long red cylinder with a yellow zigzag tube coiled around it. Can you all see that?
Well, the red cylinder actually represents a ruby crystal, and the yellow zigzag represents a tube of light, rather like a fluorescent light tube. It coils around the ruby crystal and is of course connected to the power source shown in blue. When the laser is working, this light tube flashes intermittently, on and off like a series of camera flashes. Anyway, we`ll come to that later.
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The grey disc to the left of the ruby crystal is a mirror and the one to the right of the crystal is a partial mirror, which means that it reflects part of the light, about 99% of it, in fact, but allows about 1% of the light to pass through it to the right. I think I`ve covered the main components. The large green circles inside the crystal represent atoms, and the small blue circles inside the crystal represent atoms, and the small blue circles represent photons, or particles of light. Finally, the large red arrow coming out of the right hand side of the machine is a laser beam.
OK, so before I hand over to Zak, are there any questions at this point? There will be a chance at the end of the complete talk to ask questions, so there`s no rush. Right, so now I`m going to hand over to Zak, who`s going to cover the next section of the talk, which…
13. Match the adjectives and their opposites
| 1 | coherent | a | unusual |
| 2 | complicated | b | distant |
| 3 | conventional | c | connected |
| 4 | dormant | d | total |
| 5 | dual | e | unclear |
| 6 | isolated | f | discontinued |
| 7 | neighbouring | g | active |
| 8 | ongoing | h | simple |
| 9 | partial | i | single |
14. Describe how a laser works, using the words from the list below in their correct form. There are 2 words that you don`t need to use.
to concentrate to emit fully to absorb atom photon
partial back and forth ruby crystal coherent
The power source is located below the (1) ruby crystal and makes the tube flash on and off. Every time the tube flashes, the flashes inject energy into the crystal in the form of (2) _______, which are particles of light.
In the first stage, (3) ________ in the ruby crystal (4) __________ the energy from the light tube. When the atom absorbs a photon, it becomes more excited for a few milliseconds [ˈmɪl.ɪˌsek.ənd], and then returns to its original state and (5) __________ a new photon.
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Next, the photons travel at the speed of light (6) _______ inside the ruby crystal. At the far end of the tube, a (7) __________ mirror reflects most of the photons, about 99% of them, back into the crystal, but lets a small number, about 1%, escape from the machine.
Finally, these escaping photons form a very (8) _________ beam of powerful laser light.
Grammar
Revision
https://www.youtube.com/watch?v=fVlgzuhBi-I
Watch the video and be ready to discuss the examples mentioned in it to your group mates:
- What is the difference between active and passive structures in the sentence? Give a couple of examples from the video.
- What does he call ‘past Infinitive’?
The full Infinitive (=the Infinitive with ‘to’= the ‘to’ Infinitive)/ V-ing form
| The -ingform is used: • as a noun, mostly the name of a process. e.g. Smoking is dangerous. Walking is a good exercise. My hobby is reading memoirs. • after: love, like, dislike, hate, enjoy, prefer (likes and dislikes) e.g. I love going to the theatre. I hate being laughed at. • after: start, begin, keep, go on, stop, finish, give up. (verbs denoting start, continuation and completion) e.g. He started doing his homework at 5:00 pm. They went on adjusting the equipment. • after “go” for sports and physical activities. e.g. She went skiing last Sunday. She is ready to go shopping at any moment. • aftercertain verbs (avoid, admit, confess, deny, look forward to, mind, object to, prefer, regret, risk, spend, suggest, etc.). e.g. I don't mind helping you with the dishes. • after the expressions: I'm busy, it's no use, it's (no) good, it's worth, what's the use of, be used to, there's no point (in), can’t help, can’t stand. e.g. It's worth seeing that film. It was no use spending so much time on the problem. We couldn’t help being involved into the discussion. What is the use of doing it over and over? • after prepositions. He left without taking his coat. He was accused of stealing. |
| The to-Infinitive is used: · to express purpose. e.g. He went to buy some bread. She entered the University to become an engineer. · afterwould like / would love / prefer. e.g. I would like to visit him. I'd love to see you tonight. I prefer to stay in the town. · after certain adjectives (angry, glad, happy, sorry, pleased, annoyed, etc.). e.g. I'm glad to see you here. Tom was happy to see them. · withtoo or enough. e.g. He's too old to drive. She's clever enough to understand it. · aftercertain verbs (advise, agree, decide, expect, forget, offer, promise, refuse, want, etc.) e.g. I hope to meet him again. He decided to quit. We agreed to start our business. · afterquestion words (where, how, what, who, which). Why is not used with to-infinitive. e.g. I don't know what to do.They forgot where to turn right. We didn’t know how to switch on the device. |
Note: Some verbs can take the to-infinitive (a full infinitive) or the -ingform with no difference in meaning. These verbs are: begin, hate, like, love, prefer, start, regret, intend, forget, propose, etc.
e.g. He likes to watch / watching the birds. She regretted to have mentioned / mentioning that name. We love having / to have a lot of dogs around.
| The Infinitive without ‘to’ is used · After: modal verbs (can, must, will and others). e.g. You can leave now if you want. · After: had better/would rather. e.g. I`d rather not go out tonight. I`d better stay at home. · After: make/let. e.g. They made him pay for damage. Let him buy this car. But: in the passive: be made/be heard/be seen+infinitive with ‘to’. e.g. He was made to pay for the damage. · ‘help’ is followed by the Infinitive with ‘to’ or the Infinitive without ‘to’. e.g. Could you help me (to) fix the car? But: in the passive: be helped+ infinitive with ‘to’ e.g. She was known to have worked as a tutor. |
The Bare infinitive
15. Write what each word is followed by: the full infinitive, the bare infinitive orV –ing form. Give an example.
e.g. too young...+ full infinitive (He was too young to drive a car)
a) Enjoy
b) Promise
c) Be made
d) Object to
e) It`s no use
f) Can`t stand
g) Can`t help
h) Had better
i) Agree
j) Can
k) Would like
l) Refuse
m) avoid
16. Complete the sentences using the Infinitive or V–ing form.
e.g. City life is too busy for me; I really miss living in the country.
a) We had to postpone … tennis because of the bad weather.
b) She goes … at the pool every weekend.
c) If you keep … so much, you`re bound to get fat.
d) She`s been training so hard recently that she deserves…the race.
e) He couldn`t sleep, so I suggested…some warm milk.
f) Because of his fear of jellyfish (медуза), he doesn`t like… in the sea.
g) I`d really like … my uncle in Chicago one day.
h) Mr Roberts is too old … as he used to.
i) Before the interview, I was required … an application form.
j) Becoming an Olympic athlete involves … for years.
k) I much prefer … e-mails to …. on the phone.
l) Let me be the first … you on your remarkable success.
m) I`m sorry … that I`ll be unable to attend the meeting tomorrow.
n) It` no use … to university if you don`t intend to study.
o) I think you should give up … because you have a very poor voice.
https://www.youtube.com/watch?v=XZupSm_EyHA
17. Watch the video, use the following key notes and be ready to explain the difference in the meaning.
| They stopped to buy a coffee. VS I`ve stopped buying coffee. |
| I regret telling you about singing competition, now everybody knows I have entered. I regret to tell you that your application has been unsuccessful. |
| We went on talking for hours. We went to talk. |
| For you: forget to do something._________________________________________________________ forget doing something.________________________________________________________ |
18. Study some more words. Remember the use and meaning.
| Verb | Infinitive with ‘to’ meaning | V-ing form meaning |
| Remember | = remember to do smth e.g. Remember to read the instructions. | = to recall a past event e.g. I don`t remember meeting Al before. |
| Try | =do one`s best; attempt e.g. She tried hard to cope with her new job. | =do smth as an experiment e.g. Try adding some more sauce to your pasta. |
| Mean | =intend to e.g. He means to move to Newcastle. | =involve e.g. Working harder means getting more money. |
| Want | =wish e.g.I want to find a better job. | =smth needs to be done e.g. Your dress wants cleaning. |
| Be afraid | Be afraid to=be too frightened to do smth) e.g. I am afraid to drive over the old bridge. | Be afraid of= may happen E.g. She is afraid of breaking her leg if she jumps over the wall. |
| Be sorry | Be sorry+ to-inf=regret e.g. I`m sorry to hear he has been injured. | Be sorry for=to apologize e.g. I`m sorry for misunderstanding/having misunderstood what you said |
| Hate | =hate what is about to do e.g. I hate to interrupt, but I must talk to you | =feel sorry for what one is doing e.g. I hate making you feel uncomfortable. |
| Prefer | =specific preference e.g. I`d prefer to have an early night tonight. | =in general e.g. I prefer reading a book to watching YouTube. |
19. Put the verbs in brackets into the V–ing form or the Infinitive.
e.g. Tom stopped to pick up(pick up) his washing on the way home.
a) If you don`t stop … (smoke), you`ll make yourself ill.
b) Try …(phone) John at the office if he`s not at home.
c) I tried my best …(finish), but there just wasn`t enough time.
d) He was promoted in 2015 and went on …(become) a company director.
e) The band went on … (play) even after the lights had gone out.
f) ‘Why is the baby crying?’ ‘I think he wants … (feed).’
g) Sharon wants …(talking) to you.
h) Jane was afraid … (show) her school report to her parents.
i) I`m afraid of … (lose) my way in the forest.
j) What do you mean … (do) with all that money?
k) Playing a musical instrument well means … (practise) for years.
l) I regret … (inform) you that your husband has been arrested.
m) She regrets … (spend) so much money on her new dress.
n) Do you remember … (ride) a bicycle for the first time?
o) Remember … (prepare) for the next test.
p) I`d prefer … (pretend) I didn`t hear what you just said.
q) I prefer … (downloading) books from the Internet to … (buy) them.
r) Don`t forget … (bring) some cash in case they don`t accept credit cards.
s) I was sorry … (hear) about you failing the exam.
t) He said he was sorry for … (speak) to you so rudely.
u) Oh no! I totally forgot … (turn off) the cooker.
v) I`ll never forget … (sail) through that storm in the Atlantic.
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